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Autumn Leaves/Transcript
Transcript Text reads: The Mysteries of Life with Tim and Moby A boy, Tim, stands in front of an autumn landscape. Orange, brown, and yellow leaves fall from trees. Tim grabs a typed letter that is blowing in the wind and reads from it. TIM: Dear Tim and Moby, Why do leaves change colors in the fall? From, Chelsea. Tim stands next to Moby. TIM: I've been waiting for someone to ask this one. As plants prepare for winter, they go through changes that affect the color of their leaves. An image shows a tree filled with orange, yellow, and brown leaves. TIM: Leaves are green to begin with because they contain a substance called chlorophyll. Green plants use chlorophyll to transform sunlight into energy, in a process called photosynthesis. Chlorophyll reflects green light, while absorbing blue and red and absorbs other colors of light. An image shows a a green leaf leaf and a close-up of chlorophyll. A ring of light surrounds the leaf, with arrows pointing from the light to the leaf. TIM: That’s what makes leaves look green. In the fall, weather starts to cool off. Days get shorter and there are fewer hours of sunlight. An image shows sunlight streaming through branches filled with green leaves different shades of green leaves. An animation shows the hours of sunlight decreasing. TIM: In the fall, the weather starts to cool off. Days get shorter and there are fewer hours of sunlight. An animation shows an orange tree between two houses. The daylight fades and is replaced with a dark sky and the moon. TIM: Because of that, since there isn't enough light or water for photosynthesis, so trees stop producing making chlorophyll. An animation shows green trees surrounding a dirt path. Two of the treetops turn orange. TIM: As what’s left of the chlorophyll in the leaves begins to break down, and other types of pigments show up. An animation shows a leaf filled with green dots, representing chlorophyll. As the chlorophyll fades away, dots in different shades of red and brown take their place. TIM: Pigments are substances that produce color. The ones you see in yellow, orange, and brown leaves are called carotenoids. They’re what make carrots orange and corn yellow. Carotenoids are there even when trees are green, but there’s so much chlorophyll you can’t see ‘em.we begin to see two different pigments called carotenoids and anthocyanins. They were there even when the tree was green, but there was so much chlorophyll you couldn't see 'em. A split-screen image shows the carotenoid colors, as well as a carrot and an ear of corn on one side of the screen. An animation shows how leaves lose their chlorophyll and their colors change. An image of green grass and treetops is shown on the other side. TIM: Carotenoids produce yellow, orange, and brown colors. They're what makes carrots orange and corn yellow. Anthocyanins work differently: This type of pigment isn’t present in leaves year-round, but instead forms in the fall. Anthocyanins produce red, purple, and pink leaves. They’re also what make apples red and berries purple. Side by side images show the carotenoid colors and anthocyanin colors, and the fruits and vegetables associated with each color group. The word “pigments” fills the background. TIM: So in the fall, when trees sense a change in the weather, they change colors. An image shows the leaves in various fall colors. MOBY: Beep. TIM: Well, there are some other factors at play, too. Weather and climate affect how dull or bright the fall colors may look. And depending on what part of the world you’re in, the leaves may not change color at all! Like in tropical rainforests, where the days stay about the same length year-round. Images show a lush, green rainforest. Sunlight streams through the treetops. MOBY: Beep. Moby holds two gold autumn leaves. One is brighter than the other. TIM: And depending on what part of the world you're in, the leaves may not change color at all. An image shows a hot, tropical setting. Moby is wearing sunglasses and a nearby island is covered with greenery. TIM: In the winter, when there is the least sunlight, the leaves dry up and drop off. An animation shows snow falling on a leafless tree. MOBY: Beep. Moby walks over to a pile of leaves on the ground. TIM: In the spring, the days start getting longer again, so trees grow new green leaves. Then when spring comes again and the sun is back, the trees grow new green leaves. An animation shows green leaves sprouting on a the tree. An image shows green leaves on the trees. MOBY: Beep! Moby sprints and jumps onto a pile of leaves. He crashes down into the pile, head first. Moby is submerged in the leaves and wiggles his legs around. TIM: Uh, I'd better go see if he's okay. Category:BrainPOP Transcripts Category:BrainPOP Science Transcripts